Program to generate an aircrew display aid to assess JAM effectiveness

ABSTRACT

The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter&#39;s coverage relative to the position of the EA aircraft and to the position of any number of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour, a Jam Assessment Strobe (JAS) and text for display on a number of flexibly configurable display formats posted on display units. The JAR and JAS graphics and text will aid the EA aircrew in rapidly assessing the effectiveness of a given jamming approach.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/901,545,filed Sep. 12, 2007 now U.S. Pat. No. 7,515,096, which is acontinuation-in-part of application Ser. No. 11/820,033, filed May 30,2007, now U.S. Pat. No. 7,427,947, and a continuation of applicationSer. No. 11/901,548, filed Sep. 12, 2007, now U.S. Pat. No. 7,511,657,which is a continuation-in-part of application Ser. No. 11/820,033,filed May 30, 2007, now U.S. Pat. No. 7,427,947.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the field of computer software particularly toan improved method of displaying aircrew decision aids for use indetermining the optimum placement of an Electronic Attack (EA) aircraft.The core of the invention is a software program that will dynamicallyprovide display format options to the EA flight crew regarding a threatemitter's coverage relative to the position of the EA aircraft and tothe position of protected entities (PE). The software program generatesinformation to populate various display formats providing graphical cuesand text representing a Jam Acceptability Region (JAR) contour and a JamAssessment Strobe (JAS) as well as aircraft position. The displayformats will aid the EA aircrew in assessing the effectiveness of agiven jamming approach and assists in determining the optimum flightpath for both the PE and EA. The optimized flight paths will minimizeexposure to threat emitters allowing accomplishment of the mission.

2. Description of the Prior Art

Electronic Warfare (EW) tactics employed by EA aircraft strive to directelectromagnetic energy into a threat radar receiver with sufficientpower to prevent the threat radar receiver from accurately detecting ortracking the PE. EW includes the basic concepts of Noise Jamming andDeception Jamming. Key to the successful jamming effort is generating asignal that exceeds the expected target return signal seen by the threatreceiver and concentrating the radar jamming signal in the direction ofthe threat receiver antenna. Barrage noise jamming floods the threatradar receiver with massive amounts of electronic emissions andsignificantly degrades low technology threat receiver performance. Withthe evolution of advanced radar concepts the noise jamming approach isless effective against high technology threat emitters. Advancedtechnology threat radar emitters have led to tuning the EA jammingfrequency to match the frequency of the threat emitter and to follow anyfrequency hopping or other frequency agile characteristics the threatemitter may employ. Deception jamming requires the EA platform togenerate a signal that is similar to the target return signal the threatreceiving system expects while modifying target characteristics such asreturn signal strength, range, heading, velocity or acceleration.Overcoming multiple threat emitters employing advanced radar techniques,while transitioning a hostile area and providing protection jamming is ahigh workload environment for an aircrew. Cockpit display informationand aircrew decision aids are required to improve situational awarenessfor the EA aircrew. It is an objective of this invention to reduceaircrew workload by providing decision aids.

Systems to aid the EA flight crew decision making process in positioningthe jamming source carried by the EA are in need of improvement. Currentaids available to EA flight crew provide text and rudimentary visualcues depicting gross EA position relative to threat receiver position.Current EA systems force the flight crew to manually incorporate currentPE position relative to the position of the EA and threat receiver, thenforces the aircrew to manually determine the optimum EW countermeasureto employ driving up aircrew workload. Current systems are incapable offusing EA jamming capability with projected threat emitter performanceinformation in order to obtain optimal geometrical positioning of the EArelative to threat emitters. The novel method of combining threatemitter system characteristics with EA aircraft capabilities whilesimultaneously incorporating PE position on a series of flexiblyconfigurable display formats greatly reduces EA aircrew workload andmakes the EA more effective.

SUMMARY OF THE INVENTION

The preferred embodiment is a software program that generatesinformation to display a Jam Acceptability Region (JAR) and a JamAssessment Strobe (JAS) for a multitude of ground based threat emittersupdated in real-time. The JAR and JAS are composed of a threat emittersystem susceptibility area based on the position of the ProtectedEntities (PE) and the Electronic Attack (EA) position. The JAR and JASprovides the EA aircrew visual information depicting the currentposition of the EA aircraft in relationship to ground based threatemitters and in relationship to the accompanied PE. The PE is theaircraft in need of protection jamming. Electronic Warfare (EW) employstactics to direct electromagnetic energy into the enemy radar receiverto prevent the receiver from accurately detecting the PE. Key tosuccessful radar jamming is obtaining the proper Signal to Noise (S-N)ratio threshold. One of the most critical factors in achieving this S-Nratio is placing the EA jamming signal in the correct geometric positionto blind the threat receiver while the threat antenna is slewed in thedirection of the PE. The Jam Assessment software program and theintegrated display management algorithm that is the preferred embodimentof this invention is a real-time software application that will beemployed by the EA aircrew during prosecution of their tactical mission.The Jam Assessment software program provides the aircrew with visualcues that enable the flight crew to ascertain current jammingeffectiveness. The Jam Assessment software program receives as input EAand PE positional information. The performance characteristics of thethreat emitter and EA jamming capabilities are also received as input tothe Jam Assessment software program. The information received as inputis processed by designated computers on board the EA aircraft and usedto generate the visual cues for display on series of flexiblyconfigurable display formats that allow a rapid assessment of jameffectiveness.

For the EA to determine its instantaneous optimum position it mustcontinually ascertain the position of the PE in relationship to eachthreat emitter and mathematically generate a JAR along with its ownposition within the JAR. The Jam Assessment software program mustaccount for the interaction of the JAR and the PE position as the PEtransits its intended flight path. The Jam Assessment software programblends the position of the EA aircraft and PE aircraft with theinformation residing in an electronic library designated as anElectronic Order of Battle (EOB). The positional and EOB informationblended by the JAR program is used by the Display Management routine togenerate the graphical cues and text in a user selectable formatallowing a rapid assessment of jam effectiveness.

The Jam Assessment software program has at its core two components. Thefirst is a JAR processing algorithm which sends results to a secondcomponent, an integrated display management routine. The Jam Assessmentsoftware program and its components are executed on platform computersand display hardware to provide the user with an improved situationalawareness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing showing the various Jam Acceptability Region (JAR)contours.

FIG. 2 is a drawing showing the relationships between the JAR, thethreat emitter system, the EA and the PE flight path.

FIG. 3 is a drawing showing multiple threat emitter systems and the JARoverlap area.

FIG. 4 is a high level software flowchart showing the processing stepsfor generating the Reactive Assignment and the Preemptive Assignment JARcontours and Jam Assessment Strobe (JAS) displays.

FIG. 5 is a lower level flowchart focusing on the processing steps togenerate the Reactive Assignment JAR and JAS information.

FIG. 6 is a lower level flowchart focusing on the processing steps togenerate the Preemptive Assignment JAR and JAS information.

FIG. 7 is a drawing showing the segments that make a JAS.

FIG. 8 is a drawing showing JAS and a PE that is detectable by a threatemitter

FIG. 9 is a drawing showing a JAS and a PE that is not detectable by athreat emitter system.

FIG. 10 is a drawing showing two JAS, an effective EA and a protected PEin a representative graphical format.

FIG. 11 is a drawing of a combined JAR, JAS, EA and protected PE in arepresentative graphical format.

FIG. 12 is a drawing of undesignated threat emitters.

FIG. 13 is a block diagram depicting the high level input and functionsof the Display Management routine.

FIG. 14 is a flowchart for the blackboard housekeeping logic that isreferenced in the high level functional block diagram in FIG. 13.

FIG. 15A is a first part of a flowchart for the display logic that isreferenced in the high level functional block diagram in FIG. 13.

FIG. 15B is a second part of a flowchart for the display logic that isreferenced in the high level functional block diagram in FIG. 13.

FIG. 15C is a third part of a flowchart for the display logic that isreferenced in the high level functional block diagram in FIG. 13.

FIG. 16 is a state diagram describing user interaction with the displayformats.

FIG. 17 is a drawing containing a representative display format usinggraphical cues and text generated by the integrated display managementroutine using the results of the JAR processing algorithm.

FIG. 18 is a drawing containing a second representative display formatusing graphical cues and text generated by the integrated displaymanagement routine using the results of the JAR processing algorithm.

FIG. 19 is a drawing of a representative display format depictingadvisories, warnings and a jamming equipment control interface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Broadly stated, the present invention comprises a method and softwaremodule that efficiently and simultaneously receives disparateinformation and transforms the disparate information into usablegraphical displays. The graphical displays convey information that isused to position the EA relative to a threat emitter system. A typicalthreat emitter system is composed of an antenna, a transmitter, areceiver, a mechanism to position the antenna, electronics to processinformation received and a user interface. Key to the success of anyradar jamming technique is exceeding the Signal to Noise ratio thresholdthat is an inherent characteristic of the threat emitter system. Whenthe noise signal generated by the EA exceeds the signal return of the PEyou have defeated the threat emitter system. Likewise, if the EAgenerates a stronger yet similar signal to the actual return signal ofthe PE while shifting a PE parameter, such as range or speed, the threatemitter system will be deceived, masking the true position of the PE.Generating a jamming signal to mask the true position, speed or courseof the PE degrades acquisition and tracking performance in the threatemitter system.

Generally, threat radar coverage is viewed as the instantaneous threatradar volume swept vertically and horizontally over time through azimuthand elevation limits defined by the threat radar antenna mount. Multiplethree-dimensional concentric ellipsoids extend from the transmittingantenna and compose the threat radar volume. The threat radar volume iscomposed of a main-lobe ellipsoid, numerous side-lobe ellipsoids andnumerous back-lobe ellipsoids. The main-lobe ellipsoid extends muchfarther than any side-lobe ellipsoid or back-lobe ellipsoid. Themain-lobe ellipsoid is the primary beam that is swept across a target togenerate a return signal strong enough to be detected by a threatreceiver. One critical factor in successful radar jamming is placing thejamming signal emitted by the EA in a position to enter the threatreceiver via the threat antenna while the threat antenna is slewed inthe direction of the PE.

In addition to the geometric relationship (bearing relationship) of theEA and the PE to the threat emitter system other factors also determinethe effectiveness of the threat emitter system. The other factors arethe jamming technique and the jamming tactic employed by the EA. Tworepresentative jamming techniques are Preemptive Assignment (PA) andReactive Assignment (RA). The PA technique is invoked when the threatemitter characteristics and threat emitter location are known before themission is undertaken. The RA technique is employed when an unexpectedthreat emitter or threat emitter wave form are encountered during amission requiring the EA to adapt to the threat. Generally, the PAtechnique results in Jam Acceptability Region (JAR) contours that aresmaller in area and shorter in range relative to the JAR contoursassociated with the RA technique. A JAR is defined as the family ofpositions an EA may occupy and still provide effective jamming toprotect the PE. The difference in area and range, PA relative to RA, isattributed to the relationship of bandwidth to power. When an EA jamsthe entire known PA bandwidth for a planned threat emitter lower EA jampower is applied to any specific threat emitter frequency. When the EAdetects a threat emitter the RA jamming power may be narrowed into aband focused on the frequency of interest resulting in a JAR that has alarger area and a longer range, relative to the PA JAR.

Three representative jamming tactics are associated with three JARcontours, irrespective of activating either a PA or an RA technique.Referring to FIG. 1, two dimensional depictions of the three dimensionalJAR contours are Out of Alignment (O) 110, In Side-Lobe Alignment (S)115 and In Main-Lobe Alignment (I) 120. The Out of Alignment tactic 110means the jamming asset can be geographically located anywhere within ahemispherical region centered at the threat emitter and will remaineffective in protecting the PE. This is by-far the simplest tactic. Thecenter of JAR 110 represents the location of threat emitter system 160.A disadvantage of the Out of Alignment tactic is that the EA must beclose in range 125 to the threat antenna in order to impart adequateenergy to exceed the threat receiver signal to noise ratio, regardlessof the direction of arrival of the EA jamming signal. To overcome thisrange vulnerability the S or I tactic is used. Using either the S or Itactic necessitates maintaining a stringent geometric relationshipbetween the EA and the PE to the threat emitter system.

The S tactic results in a conically shaped JAR directly related to theside lobe radiation pattern of the threat emitter antenna. The EA iseffective anywhere within JAR 115 provided the EA does not exceed the ASrange 135.

Successful jamming of the threat emitter system using the S tacticrequires the EA to be within the side-lobe volume of the threat emitterwhile the main lobe of the threat emitter volume encompasses the PE.While the S tactic increases the standoff range for the EA, relative tothe O tactic, the EA is effective only while maintaining the geometricrelationship to the PE and to the threat emitter.

The I tactic results in a conically shaped JAR directly related to themain lobe radiation pattern of the threat emitter antenna. A twodimensional depiction of the conically shaped JAR contour is depicted inFIG. 1 item 120. The EA is effective anywhere within JAR 120 providedthe EA does not exceed I range 145.

The I tactic provides an improved EA stand off range from the threatantenna but requires that a stringent geometric relationship bemaintained between the EA and PE to the threat antenna. The I tacticrequires that the EA and PE are in alignment while the threat antennamain-lobe volume encompasses the PE, hence the narrowness of JAR 120.

Each of the techniques and tactics are combined in all permutations toproduce a set of jamming approaches to degrade the performance of thethreat emitter system. The jamming approaches are: PreemptiveAssignment-Out of Alignment (PAO), Preemptive Assignment-In Side-LobeAlignment (PAS), Preemptive Assignment-In Main-Lobe Alignment (PAI),Reactive Assignment-Out of Alignment (RAO), Reactive Assignment-InSide-Lobe Alignment (RAS), and Reactive Assignment-In Main-LobeAlignment (RAI).

A given EA jamming approach has a determinable impact upon the threatemitter radar coverage. The JAR represents a volume of space in whichthe EA may position itself to provide effective jamming to mask the PEor deceive the threat emitter system regarding the true course and speedof the PE. Generating the JAR, assessing jamming effectiveness,determining optimum positioning of the EA and conveying this informationto the EA aircrew are objectives of this invention.

Referring to FIG. 2, JAR volumes for PAO-JAR 250, PAS-JAR 230 andPAI-JAR 215 are represented as two dimensional JAR areas. A JAR definesan area in which an EA may position itself for a given jamming approachand provide protective jamming to the PE. As PE 205 progresses along itsflight path 210, PAI-JAR 215 and PAS-JAR 230 will remain centered on PE205. The EA 240 must maintain its position within PAI-JAR 215 and movealong with PAI-JAR 215 while jamming threat emitter system 160 using thePAI jamming approach. Positioning EA 240 in the corner of PAI-JAR 215places EA 240 farthest from threat emitter system 160, optimum for EAsafety while providing protective jamming. As another example, EA 260 isthe sole EA and is positioned outside of JAR contours 250, 230 and 215.EA 260 would be ineffective in jamming threat emitter 160 regardless ofthe jamming approach employed resulting in threat emitter system 160detecting and tracking PE 205. PE 205 is now vulnerable to attack.

Optionally, placing the EA 240 within PAS-JAR 230 would enable the PASjamming approach that would provide adequate protection for PE 205. Itshould be noted that the PAS jamming approach would place the EA 240closer to the threat emitter 160.

Optionally, placing the EA 240 within PAO-JAR 250 would enable the PAOjamming approach that would provide adequate protection for PE 205. Itshould be noted that the PAO jamming approach would place the EA 240even closer to the threat emitter 160.

FIG. 4 is a flowchart describing the software processing steps necessaryto generate Jam Assessment displays. After program initialization iscomplete program execution begins, item 405. Own aircraft navigationalparameters for the PE and the EA are read into memory buffers where theinformation is used to initialize navigational parameters. Thenavigational parameters are provided by a designated suite of aircraftequipment specialized to provide latitude, longitude, aircraft attitude,speed and course. An Electronic Order of Battle (EOB) is a an electroniclibrary of information functioning as a database of information relatedto the characteristics and locations for threat emitter systems likelyto be encountered on a given mission, the expected flight path of the PEand the jamming capabilities of the EA. The EOB is generated during theplanning phase of a mission and is derived from sources of intelligencespecific to the theater of operation. The EOB is downloaded intocomputer memory residing in the existing suite of aircraft equipment andis made available to the Jam Assessment software program via designatedaircraft interfaces and computers. Both the navigational information andthe EOB information are used in processing step 410 to determine the PEand EA bearing to the threat emitter and to determine whether the PElies within the range of the threat emitter system. Processing step 410is performed with the assumption that the threat emitter is functioningaccording to the EOB data and the EA is not radiating a jamming signal.

Relying on the bearing relationships between the EA and PE to the threatemitter and the maximum range of the threat emitter, the softwareperforms a check 415 to determine if the PE is within the maximum rangeof the threat emitter. If the PE is not within the range of the threatemitter a no jam required flag is set 420, the displays are cleared ofstale information in step 465, then step 475 determines program end 480or directs program control to step 410 for a subsequent iteration.

If the PE is within range of the threat emitter, step 425 determines thealignment of the EA, PE and threat emitter. If the result of alignmentcheck 425 is that the EA, PE and threat emitter are in alignment then aflag is set 430 to “I”. If alignment check 425 returns an out ofalignment result then a side lobe check is made at step 435. If the sidelobe check 435 result is positive for the PE being within the side lobethen the alignment flag is set to “S” 445. If the side lobe check 435 isnegative the assumption is the EA, PE and threat emitter are Out ofalignment and the alignment flag is set to “O” 440.

The software must now determine whether to invoke RA processing or PAprocessing. The software then checks for activation of RA 450, a checkto determine whether the EA has detected a threat emitter waveform. Ifthe result of RA 450 check is positive, the threat emitter is not in theEOB, then RA processing 455 is called. Refer to FIG. 5 for a high levelflowchart describing RA processing or the detailed description below. Ifthe result of RA 450 check is negative, the threat emitter is in theEOB, then PA processing 460 is called. Refer to FIG. 6 for a high levelflowchart of describing PA processing or the detailed description below.Both RA and PA processing routines return to the same software controlpoint in FIG. 4, a call to draw displays 470. Step 475 then determinesprogram end 480 or directs program control to step 410 for a subsequentiteration.

The call to draw displays 470 invokes the Display Management routinethat is the subject of the high level block diagram in FIG. 13. The JARand JAS information resides in a series of input buffers updated andaccessible to the Display Management routine. The Display Managementroutine executes in parallel with the JAR processing algorithm using afixed time interval (FIG. 14 item 1450) for bounding a cycle ofoperation. The Display Management routine is also capable of starting anew cycle due to a significant event (FIG. 14 item 1445). The displaysbuilt by the Display management routine convey information related tooverall EA jamming effectiveness and relative location of the PE and EAto the threat emitter.

Referring to FIG. 4 several flags (steps 440, 445 and 430) correspond tothe alignment of the PE and the threat emitter. These flags are commonto RA 455 and to PA 460 processing routines and must be set prior tocalling either RA or PA processing routines.

Referring to FIG. 5, when RA processing is invoked in step 455 (FIG. 4)program flow is routed to step 505 (FIG. 5) and RA processing 505begins. RA processing determines RAI range 510 by running the Jammer andTactics Optimization (JATO) power equation 1-1 with the variables andconstants set for the RAI jamming approach. RAS range 515 is determinedby running JATO power equation 1-1 with the variables and constants setfor the RAS jamming approach. RAO range 520 is then determined byrunning JATO power equation 1-1 with the variables and constants set forthe RAO jamming approach. The variable definitions and constants used inequation 1-1 are based on the critical threat attribute parametersresiding in the EOB, real time own aircraft navigational informationfrom the PE and EA aircraft and the characteristics of the specific RAjamming approach.

The limits of threat emitter coverage, in the presence of jamming,obtained from the JATO power equation yield a JAR contour. The constantsand variable definitions for the JATO power equation 1-1 are providedbelow.

$\begin{matrix}{\mspace{551mu}{{{JATO}\mspace{14mu}{Equation}\mspace{14mu} 1\text{-}1}{R_{\max} = \left\{ \frac{P_{R} \cdot G_{RT}^{2} \cdot \sigma \cdot \lambda^{2} \cdot G_{m} \cdot G_{i}}{\begin{matrix}{\left( {4\pi} \right)^{3} \cdot \left( {S/N} \right)_{\min} \cdot L_{RX} \cdot L_{TX} \cdot L_{rp} \cdot B_{R} \cdot} \\\left\lbrack {{k \cdot T \cdot N_{f}} + {\left( \frac{\lambda}{4\pi} \right)^{2}{\sum\limits_{i = 1}^{N}\left( {\frac{P_{J} \cdot G_{JR} \cdot G_{RJ}}{R_{J}^{2} \cdot B_{J}} \cdot \frac{\Delta\; M}{L_{P} \cdot L_{J} \cdot L_{RX}}} \right)}}} \right\rbrack\end{matrix}} \right\}^{\frac{1}{4}}}}} & \;\end{matrix}$where:

R_(max)=Maximum effective range for a threat emitter

P_(R)=Receiver Power

G_(RT)=Receiver Antenna Gain

σ=Radar Cross Section

λ=Wavelength

G_(m)=Modulation Gain

G_(i)=Integration Gain

S/N=Signal to Noise Ratio (Single Pulse)

L_(RX)=Receiver Loss

L_(TX)=Transmitter Loss

Lrp=Receiver Processing Loss

B_(R)=Receiver Bandwidth

k·T·N_(f)=constant for transmission noise figure

P_(J)=Jammer Power

G_(JR)=Jammer Receiver Antenna Gain

G_(RJ)=Jammer Receiver Gain

R_(J)=Range of Jammer

B_(J)=Jammer Bandwidth

ΔM=Modulation Change

L_(P)=Jammer Processing Loss

L_(J)=Jammer Loss

The accuracy of R_(max) is dependent upon the accuracy of the criticalthreat attribute parameters drawn from the EOB, the positionalinformation of the threat emitter system, the positional information ofthe EA and the EA jamming approach parameters.

Equation 1-1 is a variation of the well known radar range equation.Equation 1-1 is invoked for each jamming approach, for each threatemitter, and for changing PE and EA positions.

FIG. 5 further describes the steps necessary to assemble a JASrepresenting the RA-JAR information. The In alignment flag (I) ischecked at step 525 (FIG. 5). If the I flag is set then a check 530 ismade to determine whether the PE is within the RAI range of the threatemitter. If the PE is within range of the threat emitter the Jam flag isset to RAI alarm 545, the JAS color is set to red 550 and the RA routineis exited 598. If the PE is not within the range of the threat emitterthen the Jam flag is set to RAI 540 and the JAS color is set to green555 and the RA routine is exited 598. If the I flag was not set then theSide lobe (S) alignment flag is checked 535.

If the S flag is set then a check 565 is made to determine whether thePE is within the RAS range of the threat emitter. If the PE is withinrange of the threat emitter the Jam flag is set to RAS alarm 585, theJAS color is set to red 590 and the RA routine is exited 598. If the PEis not within the range of the threat emitter then the Jam flag is setto RAS 580 and the JAS color is set to green 595 and the RA routine isexited 598.

If the S flag was not set then the alignment must be Out of alignment(O). A check 560 is made to determine whether the PE is within the RAOrange of the threat emitter. If the PE is within range of the threatemitter the Jam flag is set to RAO alarm 575, the JAS color is set tored 576 and the RA routine is exited 598. If the PE is not within therange of the threat emitter then the Jam flag is set to RAO 570 and theJAS color is set to green 571 and the RA routine is exited 598.

FIG. 6 describes the steps necessary to assemble a JAS representing thePA-JAR information. After calculating the PAI range 610, the PAS range615 and the PAO range 620 the in alignment flag (I) is checked at step625. If the I flag is set then a check 630 is made to determine whetherthe PE is within the PAI range of the threat emitter. If the PE iswithin range of the threat emitter the Jam flag is set to PAI alarm 645,the JAS color is set to red 650 and the PA routine is exited 698. If thePE is not within the range of the threat emitter then the Jam flag isset to PAI 640, the JAS color is set to green 655 and the RA routine isexited 698. If the I flag was not set then the Side lobe (S) alignmentflag is checked 635.

If the S flag is set then a check 665 is made to determine whether thePE is within the PAS range of the threat emitter. If the PE is withinrange of the threat emitter the Jam flag is set to PAS alarm 685, theJAS color is set to red 690 and the PA routine is exited 698. If the PEis not within the range of the threat emitter then the Jam flag is setto PAS 680 and the JAS color is set to green 695 and the PA routine isexited 698.

If the S flag was not set then the alignment must be Out of alignment(O). A check 660 is made to determine whether the PE is within the PAOrange of the threat emitter. If the PE is within range of the threatemitter the Jam flag is set to PAO alarm 675, the JAS color is set tored 676 and the PA routine is exited 698. If the PE is not within therange of the threat emitter then the Jam flag is set to PAO 670 and theJAS color is set to green 671 and the PA routine is exited 698.

Referring to FIG. 4, RA 455 and PA 460 processing routines returncontrol to the draw display routine 470 providing the informationnecessary to draw the JAR and the JAS. The information to draw the JARand JAS is in a format suitable for further processing by the designatedaircraft display processor. Once the boundaries of the JAR contours andjamming effectiveness are determined any number of user defined displaysmay be used to present the information to the EA aircrew.

Typical displays are JARs with PE and EA positions plotted with respectto their last known or extrapolated position and a color coded JamAssessment Strobe (JAS) indicating jamming effectiveness. The length ofthe JAS represents the maximum effective range for a threat emitterexperiencing EA jamming. Each jamming approach (RAO, RAI, RAS, PAO, PAS,PAI) affects the maximum detection range of the emitter adversely. Colorcoding the JAR contours and JAS is a user preference and is limited bythe display processor and the properties of the display hardwareresiding in the EA aircraft.

In the event multiple threat emitters have overlapping coverage theoverlap volume can be determined. Refer to FIG. 3 for a two dimensionalrepresentation of the JAR overlap volume for two threat emitters. Threatemitter 160 is associated with JAR 315 while threat emitter 340 isassociated with JAR 320. Each point within every JAR has a threedimensional coordinate corresponding to latitude, longitude andaltitude. Using EOB data for azimuth and elevation scan limits, themaximum effective range of emitter coverage, positional informationdescribing the latitude, longitude and altitude for a given threatemitter, allows points in common between multiple JARs to be compared.The comparison of JAR points results in common points between the JARsto be identified and used to define an overlap in threat emittercoverage areas. Plotting EA flight path 210 through the threat emittercoverage allows assessment of the EA position with respect to jammingeffectiveness. This method of determining the JAR overlap area can beexpanded to include any number of threat emitters having overlappingcoverage and is only limited by the processing throughput of theinterfaces and computers in the EA aircraft.

Referring to FIG. 7, segment 710 represents the current effective(Jammed) range, and segment 720 represents the un-jammed range of thethreat emitter. The JAS orientation represents the geometricrelationship between the PE and the threat emitter.

Referring to FIG. 8, JAS 810 has a length that passes through PE 205indicating that PE 205 is within the detection range of the threatemitter. JAS 810 would be color coded to indicate that PE 205 is notvulnerable to attack because jamming is effective. FIG. 8 represents thescenario in which the EA is effective despite the PE position within thePAI range of the threat emitter. In the event that PE 205 drifts intoline segment 820 which results in jamming not being effective, the EAaircrew is prompted to either: maneuver to address the threat, use othertactical options such as change jam techniques, deploy a kinetic weapon,or advise the PE to maneuver further away from the threat.

Referring to FIG. 9, JAS segment 910 has a length that is short of PE205 indicating that PE 205 is not within the detection range of thethreat emitter. JAS 910 would be color coded to indicate that PE 205 isnot vulnerable to attack.

Another embodiment of this invention generates a display format asdepicted in FIG. 10. JAS 1010 and JAS 1020 represents jamming employedby EA 1030 which is positioned in the JAR overlap area of the two threatemitters. In this configuration JAS 1010 and JAS 1020 would be colorcoded green indicating that PE 205 is not vulnerable to detection byeither threat emitter.

FIG. 11 depicts another display embodiment combining the JAR and JASinformation with the relative positions of EA 1130 and PE 1140. Theexplanation for FIG. 11 is applicable to either the PA or RA jammingtechnique. Assume EA 1030 is positioned within the In alignment JAR 1120employing the PAI jamming approach. JAS 1125 calculated for the PAIjamming approach falls short of PE 1140 and would be colored greenindicating that PE 1140 is not vulnerable to attack. At a glance theaircrew can determine that PE 1140 is safe from detection by threatemitter 1150 and that EA 1130 could maneuver anywhere within JAR 1120while employing PAI jamming and remain effective in protecting PE 1140.Equally important, is the situational awareness that shifting to the PASjamming approach and maneuvering EA 1130 into JAR 1115 would provideadequate protection for PE 1140. Equally important is the situationalawareness that shifting to PAO jamming and maneuvering into JAR 1110would also provide protection for PE 1140. FIG. 11 provides criticalinformation to the EA aircrew in a format that is easy to understand, isused to ascertain jamming effectiveness and improves the ability toadapt to changing conditions. The capability to assess jam effectivenessas described in the preferred embodiment fills a need unmet by thecurrent aircraft displays.

Providing information to the EA aircrew related to detected threatemitters not currently assigned a jamming approach is critical tooverall situational awareness. FIG. 12 represents the scenario in whichthreat emitter 1250 has been defined by the EA 1230 and an assessment ofPE 1220 vulnerability has been made along flight path 1240. At thispoint threat emitter 1250 has not been assigned a jamming approach, asindicated by the dashed segment 1260. At a glance, EA 1230 is able todetermine that threat emitter 1250 is a threat that requires EA 1230jamming or that flight path 1240 needs to be altered to avoid detection.

This specification has described in detail the algorithm to generatedifferent JAR and JAS graphical elements as well as the informationsuitable for display in a textual format. The specification now turns tothe detailed description of the Display Management routine.

Referring to FIG. 13, in general the Display Management routine iscomprised of multiple distinct tasks. The first task is the BlackboardHousekeeping task 1400 which uses as input JAR Processing generateddata, advisory data, system state information and user inputs. Theresults of the Blackboard Housekeeping task 1400 are used as input tothe Prioritize Data task 1500 which assures that time critical eventsare processed first. The results of the Prioritize Data task 1500 arefed to the Publish Display Queue task 1700 which provides theinformation to drive the display units and to perform the lower prioritytasks of display maintenance. The output of the Publish Display Queuetask 1700 are used to drive platform display processors which presentinformation as depicted in the representative displays of FIG. 17 andFIG. 18. Operation of the Display Management routine (FIG. 13) will nowbe described in detail.

In general, the Blackboard Housekeeping task (FIG. 13 item 1400) assuresthat the EW system state information and external environment dataelements are within data senescence limits while eliminating anyunnecessary redundant data. Referring to FIG. 14, the BlackboardHousekeeping task is initiated 1410 by a call from the JAR Processingalgorithm (FIG. 4 step 470). Asynchronous reports from various aircraftsubsystem and jamming system components are read from a series of inputbuffers and stored in a single unified data structure that facilitatesrandom access to data elements and supports system persistence.

System persistence is the ability of the overall Display Managementroutine to recover to the last known state using a data snap-shot 1455.The data snap-shot is stored in short term memory and is composed ofattributes and values necessary to restore display functionality in theevent of a system reset or catastrophic loss of real-time data. The datasnap-shot is also stored in long term digital memory to support postflight analysis and assessment of EW system operation.

The Blackboard Housekeeping functionality includes a check for redundantdata 1415 and then deletes any redundant data 1420. Stack manipulation1425 is then performed to assure that an accessed data element is theappropriate data element. Stack manipulation 1425 is also necessary if aFirst-In-First-Out (FIFO) array of limited size is required or if aspecific time-out for data senescence is needed. A check for anystagnant data 1430 in the stack is then performed. This stagnant datacheck 1430 sets an advisory 1435 indicating that data extrapolation isnecessary 1440 for aged but usable data. It is well known within thestate of the art that velocity and acceleration information are used toextrapolate a known aircraft position over a given length of time todetermine a new position for the aircraft. A check is then made todetermine if a significant event 1445 has occurred.

A significant event is an event that has an impact upon the role of theEA in protecting the PE. A significant event may be the change inoperational status of a key piece of the EW suite, a weapon failure, asudden change in status of a PE, a sudden change in the threat emittercharacteristics or detection or loss of a threat emitter system. If asignificant event has occurred than a snap-shot 1455 is taken and storedas persistence data for storage in short term memory and storage in longterm memory on a digital recording medium.

The snap-shot 1455 of system activity is also taken periodically and iscontrolled by a snap shot timer which is checked for a time out. If thesnap shot time out has not occurred program execution continues 1460. Ifthe snap shot timer has timed out then a snap shot 1455 is taken, afterwhich program flow continues 1460.

It should be noted that the own aircraft navigation updates are anominal 1 second rate and thus becomes the primary candidate for theexecution time limit for the Blackboard Housekeeping task.

The basis for user interaction with the Display Management routine isthrough the use of a rotary of user options enabled by a push-tile. Apush-tile is a hardware button that is integral to a multi-functiondisplay unit. A push-tile is software programmable in function andlabeling. Numerous push-tiles surround the display area of the displayunit to accept user commands to control display formats and foroperating aircraft systems. A push-tile button is immediately adjacentto the label that defines the push-tile function. The push-tile buttonsare not shown in the figures as the quantity, spacing, size andappearance of push-tile buttons vary according to the size of thedisplay unit and is unique to each manufacturer.

The software to support push-tile function definition and labeling isunique to the display unit that resides in the aircraft cockpit.Configuring the push-tile labels and configuring the push-tiles tocontrol functions are necessary to implement the invention's preferredembodiment and are documented by the display unit manufacturer.

In the preferred embodiment, a user is provided positive feedback that apush-tile depression is acknowledged by observing a display update,observing a change in the box surrounding a label corresponding to agiven push-tile position or both. For the preferred embodiment, FIG. 18represents a default display format providing the user an option ofselecting between either a range and altitude display (RGAT) format or alatitude and longitude format (LTLN) (item 1820). When the userdepresses the push-tile (not shown) directly below item 1820 the displaytransitions to that of FIG. 17, an RGAT format with RGAT (item 1820)boxed. A subsequent depression of the push-tile directly below item 1820transitions the display format to a range and bearing format (not shown)or to any other user defined format. This concept is best described as arotary of display formats enabled by repeated depression of a singlepush-tile. The push-tile rotary concept is key to the operation of theDisplay Management routine. A push-tile may also be configured tooperate as an off and on switch to enable a single user defined command.

As previously discussed, the JAR processing is capable of generatinginformation related to the position of the EA and PE relative to athreat emitter. Additionally, multiple overlapping JARs can be generatedfor display. All of this information is available for display inflexible formats that are configured by the user.

Together FIGS. 15A, 15B and 15C, comprise a software flowchart for thePrioritize Data task (FIG. 13 item 1500) and Publish Data Queue task(FIG. 13 item 1700) and describe the overall design and the stepsnecessary to prepare the information received from the BlackboardHousekeeping task (FIG. 13 item 1400) for display in flexible displayformats defined by the user.

A primary function of the Display Management routine is to process timecritical user commands for displaying the information to assess jameffectiveness as well as to command changes in the type of jammingemployed by the EW aircraft. The Prioritize Data logic is based oncategories such as Time Critical, Mandatory Timed, MandatoryAcknowledge, and Optional. The Prioritize Data logic sets a prioritizedorder for designated display fields: labels, structural text, Jam ThreatAssessment text, advisory text (heading, altitude, speed, jam mode,etc.) and graphics elements such as EA and PE planned routes, projectedpositions, Threat Assessment Strobes, JAR volumes. Each display elementfalls into one of several priority categories listed in Table 1. Thedisplay elements in Table 1 are discussed in detail and defined later inthis specification.

TABLE 1 Priority Categories Mandatory Time Critical AcknowledgeMandatory Timed Optional Label status Jam Mode Change Advisory TextStructure Text Jam Threat PE Comm Graphics Elements Detailed TextAssessment OVM Advisory JAR Volumes DOA Elements OVM Elements

Each display element in Table 1 is then assigned a relative value asdescribed in Table 2, Relative Significance, which allows a processingpriority list to be generated. This Relative Significance priority listassures that the higher priority display elements that impact missionsafety and success are processed before any other lower priority displayelements.

TABLE 2 Relative Significance Time Mandatory Mandatory CriticalAcknowledge Timed Optional Priority 1 2 3 4

Prior to the start of prioritizing data a check (FIG. 15A 1502) is madeto determine if the Electronic Combat Decision Support System (ECDSS) isactively engaged in combat support processing. If the ECDSS is notactive a check (FIG. 15A 1504) will be made to determine if the JamThreat Assessment (JTA) displays have been selected by the aircrew. TheJTA displays are the series of linked formats generated by the DisplayManagement routine. If the JTA displays are selected then the JTA labelsand advisories are updated (FIG. 15A 1506) and time critical processingbegins. If the JTA displays are not selected (FIG. 15A 1508) thencontrol is routed to the end of the flowchart (FIG. 15C 1680). If thecheck (FIG. 15A 1502) for ECDSS is active then the JTA labels andadvisories are updated (FIG. 15A 1510) and time critical processingbegins.

At the core of the Display Management routine is the software engine toenable the building of flexible display formats defined by the user. Thesoftware providing the flexibility for managing the display formatsincludes logic to generate push-tile labels, textual advisories, JARgraphics and jamming commands. The logic is best represented by theDisplay Management state diagram (FIG. 16). The relationship between theDisplay Management state diagram (FIG. 16) and the software flow chart(FIGS. 15A, 15B and 15C) is that the flow chart path is driven by avariable user input controlled by the events and states shown in theDisplay Management state diagram. The push-tile driven commands thatcontrol transitions through the state diagram create very flexibledisplay formats that are only limited by the available JAR processingdata and the performance limits of the chosen display unit hardware andsoftware.

In general, entry into the state diagram (FIG. 16) begins with the PageControl event 1710 being active when either the JTA displays areselected by the user (FIG. 15A item 1504) or the ECDSS active check(FIG. 15A item 1502) is positive. A command from Page Control 1710 issent to Display Mode Control 1740 with the page type informationnecessary to build a display format. In the preferred embodiment, theinitial display format commanded by Page Control (FIG. 16 item 1710) isthat of FIG. 19 (item 1910) from which subsequent tactical displays maybe invoked. In FIG. 19 the JTA label is boxed (item 1875) indicatingthat depressing the push-tile corresponding with item 1875 has beendepressed and will transition to default display of FIG. 18 item 1880.

Referring to FIG. 18, upon transition to the default tactical format(1880) the user is provided with options to transition to any tacticaldisplay format defined by the user. Selectable tactical display formatsare indicated by labels displayed above or next to a push-tile. As anexample, two tactical display formats are selectable, RGAT (FIG. 17 item1870) or LTLN (FIG. 18 item 1880), by manipulating the push-tileassociated with display transitions 1820. The LTLN label is boxed (FIG.18 item 1820) because it has been selected by the user. When the userdepresses the push-tile 1820 corresponding to the tactical displayformats the display transitions to the RGAT format (FIG. 17 item 1870)and the RGAT label is boxed. Should the user again depress the push-tilecorresponding to the tactical display formats 1820 the displaytransitions back to the LTLN display format 1880. The number and type ofselectable displays are defined by the user.

An exit control from the TACT mode back to the JTA mode is user definedand any combination of a push-tile and a label may be programmed for useon the displays. The exit control must communicate with the Page Controlstate (FIG. 16 item 1710) to define the page type for processing by theDisplay Mode Control (FIG. 16 item 1740) state.

Referring to FIG. 19, the JTA display 1910 has a number of fieldscontaining time prioritized information (1835, 1940, 1950) as well asthe push-tile labels (1920, 1922 and 1923) that provide a user interfacewith the Display Management routine. The jam options labels 1835 areassociated with a rotary push-tile which allows the user to selectManual (MAN) or fully Automated (AUTO) jam control as the display state(FIG. 16 item 1730). While the MAN state is selected the ECDSS willmonitor jam asset management parameters and provide the user with jamcontrol advisories in an Action Box 1940. The Action Box states areunder the control of the Action Box state machine (FIG. 16 1720).

The portion of the Display Management state diagram (FIG. 16) and theflowchart (FIG. 15A) pertaining to the handling of the Time Critical andMandatory Acknowledgement items in Table 1, the first of which pertainto MAN and AUTO operation (FIG. 19 item 1835), are now described.

The Action Box state 1720 sends a selection event to the Issue Commandstate 1725 reflecting any one of a series of user defined jam controlrecommended actions and corresponding labels. The user is then providedwith options to either accept (ACT item 1920) the recommended action,step to the next recommended action (NXT item 1922), or reject therecommended action (RJCT item 1923). The recommended actions are undersoftware control and user defined. Three representative recommendedactions are presented in FIG. 19 item 1940.

Referring to FIG. 19, the manual mode is active 1835 and the ECDSS hasdetermined that the jamming Pod assigned to the current threat is notable to perform the assigned tasking and has generated a boxed PODRE-ASSIGN recommended action in the Action Box 1940. The ECDSS has alsogenerated several other recommended actions such as a one versus manycentroid (OVM CENTROID) as well as a recommended action to issue a PEcommunications command (PE COMM CMND) to alert the PE that it is off ofthe flight plan. Since the POD RE-ASSIGN recommended action is selectedin the Action Box 1940 if the operator selects the ACT 1920 push-tile,the ECDSS system will activate the jam assignment change required toaddress the existing jam failure situation. If the operator selects theRJCT 1923 push-tile, the Pod Re-Assign advisory in Action Box 1940 willbe removed. If the operator selects the NXT 1922 push-tile the systemwill step to the next recommended action in the Action Box 1940 list,here it is OVM CENTROID.

The PE alert indicating that the PE is off the flight plan (PE OFF PLAN)is written into an advisory text field 1950. If the user steps to the PECOMM CMND using the NXT (1922) push-tile and elects to reject the PECOMM CMND recommendation using the RJCT push-tile (1923) the PE OFF PLANadvisory will persist in the advisory text field (1950). Any number ofalerts may be written into the advisory text field 1950 and tied to anynumber of recommended actions displayed in the Action Box 1940. Theflexibility to display JAR information and interact with the displayedJAR information is the essence of the preferred embodiment of theinvention as described in the Display Management state diagram (FIG. 16)and as shown in the representative display format drawings (FIGS. 17, 18and 19).

Referring to FIG. 15A, a series of checks are performed to determine thestate of the jam mode. A first check 1512 is made to determine if a JamMode Change is accepted. If the check 1512 returns a positive,indicating that the user has selected ACT (FIG. 19 item 1920), the SetMode Command 1514 is enabled and any pending change is cleared 1516. Ifthe first check 1512 returns a negative, a Jam Mode Change has not beenaccepted. A second check 1518 is then made to determine if a Jam ModeChange has been rejected. If the second check 1518 returns a positive,indicating that the user has selected RJCT (FIG. 19 item 1920) anypending change is cleared 1516 leading to a third check 1520. If thesecond check 1518 returns a negative, a Jam Mode Change has not beenrejected leading to the third check 1520. The third check 1520determines whether a Jam Mode Change needs to be activated as a resultof the user selecting ACT (FIG. 19 item 1920). If the result of thethird check 1520 is positive an advisory is posted 1522 and the ActionBox state (FIG. 16 item 1720) sends an event to the Issue Command state(FIG. 16 item 1725) to issue an appropriate command to the ECDSS.

Referring to FIG. 15A, a series of checks are now performed to determinewhether a PE communications command (PE COMM CMND, FIG. 19 item 1940)has been issued by the EA and sent to the PE. The PE communicationscommand is the second Mandatory Acknowledgement task required perTable 1. A first check 1524 is made to determine if a PE communicationscommand is accepted. If the check 1524 returns a positive, indicatingthat the user has selected ACT (FIG. 19 item 1920), the Set PE Command1526 is enabled and any pending PE communication advisory is cleared1530. If the first check 1524 returns a negative, a PE communicationscommand has not been accepted. A second check 1528 is then made todetermine if a PE communications command has been rejected. If thesecond check 1528 returns a positive, indicating that the user hasselected RJCT (FIG. 19 item 1920) any pending PE communication advisoryis cleared 1530 leading to a third check 1532. If the second check 1528returns a negative, a PE communications command has not been rejectedleading to the third check 1532. The third check 1532 determines whethera PE communications command needs to be activated as a result of theuser selecting ACT (FIG. 19 item 1920). If the result of the third check1532 is positive an advisory is posted 1534 and the Action Box state(FIG. 16 item 1720) sends a User Selection event to the Issue Commandstate (FIG. 16 item 1725) to issue an appropriate command to the ECDSSsuite. Program execution continues with item 1535 providing a transitionbetween FIG. 15A and FIG. 15B.

Referring to FIG. 15B, a series of checks are now performed to determinewhether an OVM centroid (OVM CENTROID, FIG. 19 item 1940) displayreference option has been selected by the user. The OVM centroid displayreference option is the third Mandatory Acknowledgement task requiredper Table 1. A first check 1636 is made to determine if an OVM centroiddisplay reference option is accepted. If the check 1636 returns apositive, indicating that the user has selected ACT (FIG. 19 item 1920),the Set OVM centroid display reference command 1642 is enabled and anypending OVM centroid display reference advisory is cleared 1646. If thefirst check 1636 returns a negative, an OVM centroid display referencecommand has not been accepted. A second check 1640 is then made todetermine if an OVM centroid display reference command has beenrejected. If the second check 1640 returns a positive, indicating thatthe user has selected RJCT (FIG. 19 item 1920) any OVM centroid displayreference advisory is cleared 1642 leading to a third check 1644. If thesecond check 1640 returns a negative, an OVM centroid display referencecommand has not been rejected leading to the third check 1644. The thirdcheck 1644 determines whether an OVM centroid display reference commandneeds to be activated as a result of the user selecting ACT (FIG. 19item 1920). If the result of the third check 1644 is positive anadvisory is posted 1646 and the Action Box state (FIG. 16 item 1760)sends a user Selection event to the Display Control state (FIG. 16 item1740).

Software execution continues with the processing of those tasks in theMandatory Timed and Optional categories of Table 1. Referring to FIG.15B, the Update Advisory Text step 1648 is performed and updates theadvisories posted in the advisory text field (FIG. 19 item 1950). Theadvisories are user defined derived from the information supplied by JARprocessing, EOB, ECDSS operational status, PE status and navigationalaids.

As previously described, the preferred embodiment of the DisplayManagement routine includes two types of display formats, JTA (FIG. 19)and TACT (FIG. 17 and FIG. 18). The JTA display is discussed above. TheTACT display format contains graphical display elements such as a JAR(FIGS. 1, 2, 3 and 11), a JAS (FIGS. 7, 8, 9, 10, 12), PE position, EAposition and planned flight paths. FIG. 17 item 1870 and FIG. 18 item1880 are representative of the types of graphical displays a softwareprogrammer skilled in the art of aircraft display graphics mayimplement. The TACT display formats are essential as an aircrew decisionaid, which is object of this invention. Graphical representation of thethreat emitter's effectiveness in the presence of active EA jammingallows the EA aircrew to rapidly assess the vulnerability of anyassigned PE.

Referring to FIG. 15B, after the advisory textual elements are updated1648 a series of checks are made to properly maintain the TACT displaygraphics. First a check 1650 is made to determine whether or not theTACT graphical displays are active. If the response is positive and theTACT graphics are active the TACT graphics are updated 1652. If theresponse to the check 1650 is negative the graphics are cleared frommemory 1654 and Display Management execution continues. The displayunits posting the JTA displays are used by other platform systems fordisplay purposes that may be of more interest to the user. Consequently,there may not be a display unit available for posting the JTA displays.Item 1635 provides a transition between FIG. 15B and FIG. 15C as programexecution continues.

In general, it is well known by those skilled in the art of programmingaircraft displays that user preferences encompassing display type,display reference point and the structure of the displayed elements varyand are best implemented in software. Examples of common display typesare range versus bearing, azimuth versus elevation and direction ofarrival. Examples of common reference points are aircraft stabilized andearth stabilized. Examples of structure for the displayed elements arean OVM display, viewing all of the JAR data at once, viewing all of theJAS data at once, displaying selected portions of the JAR or JAS data aswell as viewing PE and EA information. The Display Management routineincludes a Display Preference state 1760 containing the software code togenerate combinations of display types, display references and displayelement structures.

Referring to FIG. 15C, after the maintenance of the TACT graphics iscompleted a series of checks are made to determine the user preferencesfor the viewing the displayed graphics and text. A first check 1662 ismade to determine if the user preference for the display type isdirection of arrival (DOA). If DOA check 1662 is positive then a DOAUpdate 1664 event is sent to the Display Reference state 1760. If theDOA check 1662 is negative the DOA is cleared 1666 by the DisplayReference state 1760. A second check 1668 for OVM active is made todetermine if the user preference for the display type is OVM. If OVMcheck 1668 is positive then an OVM Update 1670 event is sent to theDisplay Reference state 1760. If the OVM check 1668 is negative the OVMis cleared 1672 by the Display Reference state 1760.

The DOA and OVM check and response logic blocks in FIG. 15C arerepresentative of the type of logic blocks that may be duplicated forany number or combination of user display preferences. The presentinvention provides the flexibility to customize the aircrew decision aiddisplays and the above examples are not meant to limit the scope of theinvention to the displays disclosed. Any limitation encountered isrelated to the processing capability and size of the digital memory ofthe computer selected by the user.

Referring to FIG. 15C, after the display of the highest priority displayinformation in Table 1 is completed a series of checks are made todetermine whether any of the optional text requires updating. Theoptional text consists of those display elements that may be droppedfrom a JTA or TACT display should the display processor functionalitydegrade as it reaches it's processing throughput limits. Optional textis of two types, Structure Text and Detailed Text. Examples ofStructural Text are the axis for the RGAT display (FIG. 17 items 1812and 1814), the axis 1812 labels in feet (FT), the axis 1814 labels andnumbers in nautical miles (NM). An example of Detailed Text is the JTApage identification text, JAM THREAT ASSESSMENT (FIG. 19 item 1950). Afirst check 1674 is made to determine if the optional text requiresupdating. If the Detailed Text Active check 1674 is positive then anUpdate Text 1676 event is sent to the Display Preference state 1760. Ifthe Detailed Text Active check 1674 is negative then an Update StructureText 1678 event is sent to the Display Preference state 1760. Executionends with step 1682.

In the preferred embodiment, a user is provided a number ofopportunities to configure the displays to best represent the availableinformation through the use of a rotary. Referring to FIG. 17, item 1805is a cluster of labels associated with push-tiles for controlling thetime reference for the display format. One label corresponds toincrementing the time (FWD) and another label corresponds todecrementing the time (BCK). The boxed numerical value (3) correspondsto the number of minutes into the future the displayed information isextrapolated. The aircrew may change the extrapolation time eitherforward to four minutes or back to two minutes as desired. In thepreferred embodiment the maximum extrapolation time is set to fiveminutes. The duration of extrapolation time windows are under control ofthe software programmer subject to processing throughput constraints anda user requirement.

Referring to FIG. 16, a user selection of a FWD or BCK push-tile willsend a Change event from the User Command state 1755 to the TimeInterval state 1750 which in turn sends an Update event to the DisplayControl state 1740 for display processing. The Display Control state1740 then sends a Data event to the Time Interval state 1750 which sendsan Update event to the User Command state 1755 providing feedback thatthe command and response to the command is complete and ready fordisplay on the display units.

In yet another preferred embodiment, a user is provided anotheropportunity to configure the displays to best represent the availableinformation through the use of a rotary. Referring to FIG. 17, item 1810is a cluster of labels associated with push-tiles for controlling thethreat graphics displayed. In this example, the JAR graphic displayedhas an index of one as represented by the boxed numeral one. A JARgraphic is composed of the JAR coverage areas (FIG. 17 item 215, 230,and 250) and the relative PE and EA positions as shown in FIG. 17. EachJAR graphic is assigned an index in a display list for record keepingand assuring consistency across the display formats as the displayconfiguration commands are processed. By depressing the NXT 1810push-tile the boxed numeric increments from a one to a two correspondingto the second threat in the threat display list. At this point, the JARgraphic for the first threat is removed from the display allowing theuser to only view the second threat JAR graphic, not shown. A subsequentdepression of the NXT 1810 push-tile increments to the third threat inthe threat display list and leads to the removal of the second threatJAR graphic. Repeated depressions of the push-tile associated with thePREV (1810) label decrements the numeric to its minimum value providingthe opportunity for the user to rotate through the threat display listin the opposite direction. The JAR graphics in the threat display listmay be individually viewed in this manner until the rotary steps to anall (ALL) position or a multiple (M) position.

The ALL position allows the user to view all of the threats in thethreat display list simultaneously. This results in a cluttered displaywith many overlapping display elements in the event that there arenumerous threats with closely space JAR graphic symbols. To alleviatethis problem the user is provided with a multiple (M) option in therotary. The M option allows the user to cursor designate, or hook, anyindividual threat JAR graphic and remove that JAR graphic symbol setfrom the display. This allows the user to view the desired number ofthreats in the threat display list.

The ability of the user to control the number of displayed threats is afeature that is necessary to de-clutter the display format allowing theuser to focus on any particular threat should multiple overlapping JARgraphics render the display unreadable.

User selection of a NXT or PREV push-tile will send a Change event fromthe User Command state 1785 to the Threat Quantity state 1780 which inturn sends an event to the Display Control state 1740 for displayprocessing. The Display Control state 1740 then sends a Data event tothe Threat Quantity state 1780 which sends an Update event to the UserCommand state 1785 providing feedback that the command and response tothe command is complete and ready for display on the display units.

In still yet another preferred embodiment, a user is provided anotheropportunity to configure the displays to best represent the availableinformation through the use of a rotary. Referring to FIG. 17, item 1815is a cluster of labels associated with push-tiles for controlling thedisplay of threats associated with a particular PE. This feature isuseful in the event that a user is interested in viewing all of thethreats that are capable of detecting a particular PE. By depressing theNXT push-tile the boxed numeric increments from a one to a two if thereis a second PE available in the display list. All of the threats thatcan detect the second PE will be displayed and the threats associatedwith the first PE are removed from the display. Repeated depressions ofthe NXT push-tile will increment the numeric to it's maximum value thento an ALL choice. The ALL will return all of the PEs and the associatedthreats to the display list allowing the user to once again view all ofPEs and threats. Repeated depressions of the PREV push-tile decrementsthe numeric to it's minimum value providing the opportunity for the userto rotate through the PE list in the opposite direction. Rotation to theALL position from the minimum direction returns all of the PEs andthreats to the display.

User selection of a NXT or PREV push-tile will send a Change event fromthe User Command state 1795 to the PE Quantity state 1790 which in turnsends an event to the Display Control state 1740 for display processing.The Display Control state 1740 then sends a Data event to the PEQuantity state 1790 which sends an Update event to the User Commandstate 1795 providing feedback that the command and response to thecommand is complete and ready for display on the display units.

The Time 1805, THRT 1810 and PE 1815 groups of labels are common acrossmultiple display formats as shown in FIG. 18. In the preferredembodiment, it is necessary to provide consistency in display operationto the extent possible. Referring to FIG. 17 and to FIG. 18, thepush-tile legends are placed in the same position and retain the samefunctionality as the display formats are transitioned. The consistencyin display operation also provides the additional benefit of minimizingthe software programming and minimizing execution time for programoperation regarding the management of displays.

In order to more effectively provide information to the user thepreferred embodiment incorporates a color scheme for displaying text andgraphics. The Display Management routine needs to assure thatunambiguous caution and advisory cues are provided to the user and thathigh priority caution and advisory cues are readily identifiable. In thepreferred embodiment, all text and graphic displays will utilize adefined set of standard colors to convey information as listed in Table3.

TABLE 3 Display Colors Color Meaning Use White Informative structureBody Text, Title, Heading, etc. Green No action required Dynamicgraphic/text Cyan Advisory, Action Eminent Dynamic graphic/text (Blue)Yellow Caution, Action Impending Dynamic graphic/text Red Warning,Action Required Dynamic graphic/text Pink Informative, Possible ActionDynamic graphic/text (Flesh) Black None Background

The capability the applicant's invention to rapidly provide situationalawareness to the aircrew by taking advantage of JAR processinginformation and in turn displaying the results of JAR processing in ahighly flexible format controlled by the aircrew is best illustrated byexample.

The example is, the user is presented with five overlapping JAR graphicsassociated with three PEs drawn on a single RGAT (FIG. 18) displayformat. The resulting display is cluttered with text and graphicsimpeding a quick assessment of the effectiveness of the EA. The EA isassigned PE1 as a primary assignment and wishes to view only thosethreats for PE1. The user depresses the NXT push-tile to rotate the PEdisplay numeric from ALL to 1. The display now depicts three threatsassociated with PE1 while simultaneously suppressing the text andgraphics for PE2 and PE3. The user then determines that emitter threattwo is not relevant due to the color of the threat graphics and electsto de-clutter the display by removing all traces of threat emitter twographics and text. The user then depresses the NXT push-tile until the Mis present then designates threat two for deletion from the displaylist. The user now is provided the information to assess the currenteffectiveness of the EA in a clear and de-cluttered format. The userthen desires a view of the scenario two minutes into the future anddepresses the Time FWD push-tile until the numeric is 2. The display isupdated with the appropriate extrapolation and the user then assessesthe future effectiveness of the EA. The user is able to rapidly assessthe effectiveness of the EA in protecting the PE and obtaining asituational awareness quickly and with little effort.

It is not necessary to limit the implementation of the invention to thepreferred embodiments described in this specification, to currentlyexisting platform computers, to currently existing platform interfacesor to current electronic warfare capabilities. The nature of thisinvention is a JAR processing algorithm which invokes an embeddedsoftware routine to build displays that are readily adaptable to anumber of platforms, user requirements and user environments.

The terms aircraft and platform as well as aircrew and user have beenused throughout this specification interchangeably. One skilled in theart of electronic warfare will adapt the applicant's invention to anyplatform that operates in any area which requires rapid assessment ofdefensive and offensive electronic warfare capability.

1. A method for producing a linked set of graphical displays forassessing jamming effectiveness of an electronic aircraft wherein saidgraphical displays convey information which is used by said electronicaircraft for positioning relative to a threat emitter system, saidmethod comprising the steps of: providing a digital computer having acomputer software program residing within an internal memory of saiddigital computer, wherein said computer software program includesprogram code for producing said graphical displays; monitoring a timerwithin said digital computer which sets a maximum time allotted for asoftware execution cycle of said computer software program; comparing afirst element in a current memory stack with a second element in aprevious memory stack to identify a redundant data element, wherein saidcurrent memory stack and said previous memory stack reside within saiddigital computer; deleting said redundant data element from said currentmemory stack; compacting said current memory stack to remove traces ofsaid redundant data element deleted from said current memory stackwherein said traces of said redundant data element comprise an emptymemory cell and a software pointer to said empty memory cell; evaluatinga time stamp which is affixed to an active data element in said currentmemory stack to determine if said active data element requires a timebased extrapolation; creating a system snap shot for storage in digitalmemory within said digital computer wherein said system snap shot is acopy of said current memory stack; processing said current memory stackin a priority order from a high priority active data element to a lowpriority active data element; formatting a plurality of interrelateddisplay screens located onboard said electronic aircraft, each of saidinterrelated display screens having a set of textual characters and aset of graphical symbols wherein said set of graphical symbols and saidset of textual characters represent a result of a jamming acceptabilityregion processing algorithm; accepting a plurality of user customizationcommands to modify formats of said plurality of interrelated displayscreens onboard said electronic aircraft wherein said plurality of usercustomization commands are directed at said set of textual charactersand said set of graphical symbols; generating a color coded series ofadvisories for an aircrew onboard said electronic aircraft and a colorcoded series of warnings on said plurality of interrelated displayscreens for viewing by the aircrew onboard said electronic aircraftwherein a specific color is determined by the results of said jammingacceptability region processing algorithm; controlling an operation ofan electronic warfare jamming device using an operational controlpresented on any one of said plurality of interrelated display screens,wherein the aircrew on said electronic aircraft using said operationalcontrol controls the operation of said; alerting said plurality ofprotected entities to said jamming effectiveness determined by theresult of said jamming acceptability region processing algorithm; andupdating said plurality of interrelated display screens onboard saidelectronic aircraft corresponding to a motion of said electronic warfareplatform, corresponding to a motion of said plurality of protectedentities and corresponding to changes in an operation of a plurality ofthreat emitters.
 2. The method of claim 1 wherein said system snap shotis stored in a short term digital memory in said digital computeronboard said electronic aircraft.
 3. The method of claim 1 wherein saidsystem snap shot is stored in a long term digital memory in said digitalcomputer onboard said electronic aircraft.
 4. The method of claim 1wherein said plurality of user customization commands includes deletingsaid set of textual characters and said set of graphical symbols fromsaid plurality of interrelated display screens onboard said electronicaircraft.
 5. The method of claim 1 wherein said plurality of usercustomization commands includes adding said set of textual charactersand said set of graphical symbols to said plurality of interrelateddisplay screens onboard said electronic aircraft.
 6. The method of claim1 wherein said user customization commands are implemented by aplurality of software programmable interfaces wherein said plurality ofsoftware programmable interfaces have a label of alphanumericcharacters, have a consistent position on a display unit and retain saidlabel and said consistent position while said user transitions throughsaid plurality of interrelated display screen onboard said electronicaircraft.
 7. The method of claim 1 wherein said user customizationcommand includes a display frame of reference choice for said set ofgraphical symbols said choice is either an earth stabilized frame ofreference or a platform stabilized frame of reference.
 8. The method ofclaim 1 wherein said jamming acceptability region processing algorithmincludes an execution of a jammer and tactics optimization powerequation wherein said jammer and tactics optimization power equationaccepts a plurality of input data including a first data stream sentfrom an electronic order of battle, a second data stream sent from anavigation system, a third data stream sent from a protected entity anda fourth data stream sent for an electronic warfare suite onboard saidelectronic aircraft.